Sewerage treatment facilities which improve the quality of fluid waste often have odor problems associated with them. A common source of odors at such facilities are sludge ponds which retain fluid waste for extended periods of time to permit waste material to settle and be biodegraded into harmless sludge. Such ponds can be and most often are extended over very large areas in order to accomodate the large fluid volume generated by sewerage treatment facilities and the necessary residence time of fluid in the pond in order for settling and biodegradation to take place. Typically, such treatment or settling ponds can have surface areas ranging from hundreds of square feet to acres.
Prior attempts to control odors from such treatment facilities have generally been limited to treatment of the air mass surrounding the periphery of the pond with a masking or substitute odor such as provided by perfume or the like. Typically, an extended pipe has been placed near the periphery of the pond and masking vapor has been dispensed into the atmosphere through openings in the pipe wall. When dispensing pipes are placed only on the periphery of the pond, wind direction can be a substantial factor in the effectiveness of such peripheral units since the wind may serve to dispense the ordor in a pattern not reached by the limited perimeter odor abatement gas coverage.
Alternatively, treatment has been conducted simply by dispensing odorant into the air mass near the pond with reliance on the wind to disperse the odorant and thereby mask the effect of the odor causing material. Such systems are highly inefficient because of the large amount of odorant usually required and problems of dispersion into the air mass containing the odor causing material.